From: Logan Capaldo <logancapaldo@...>
Date: 2006-01-18T06:59:04+09:00
Subject: Re: basic question about Fixnum & Integer


On Jan 17, 2006, at 4:44 PM, Guillaume Marcais wrote:

> Is it true that RubyGems requires mathn? It seems so to me:
>
> gus@guslaptop ~]ruby -e 'p(5.lcm(3))'
> -e:1: undefined method `lcm' for 5:Fixnum (NoMethodError)
> gus@guslaptop ~]ruby -rubygems -e 'p(5.lcm(3))'
> 15
> gus@guslaptop ~]ruby -v
> ruby 1.8.4 (2005-12-24) [i686-linux]
> gus@guslaptop ~]gem -v
> 0.8.11
>
>
> That gives me somewhat of an uneasy feeling. How many core  
> tampering libraries does RubyGems requires that may make me rely on  
> methods which are not really in the core?
>
> Guillaume.
>
> Tom Allison wrote:
>> Jules wrote:
>>> No, you don't have to require integer, because it is in the core.  
>>> The core is always available. You can read the docs here:
>>>
>>> http://www.ruby-doc.org/core/
>>>
>>> And there is a standard library too:
>>>
>>> http://www.ruby-doc.org/stdlib/
>>>
>>> Most of these are not available by default. If you want to use a  
>>> YAML parser, you have to require YAML.
>>>
>> Thanks for the references.
>> For some reason I can't get my installation of Ruby to do what the  
>> examples show:
>> 6.lcm 7
>> return
>>  >> 6.lcm 7
>> NoMethodError: undefined method `lcm' for 6:Fixnum
>>         from (irb):17
>>         from :0
>>  >> 6.lcm(7)
>> NoMethodError: undefined method `lcm' for 6:Fixnum
>>         from (irb):18
>>         from :0
>> This is too simple to get wrong?
>
>

It doesn't require mathn, it requires rational.rb

irb(main):013:0> 1/2
=> 0
irb(main):014:0> require 'rubygems'
=> true
irb(main):015:0> 1/2
=> 0
irb(main):016:0> exit

logan:/Users/logan% ruby -e 'p(5.lcm(3))'
-e:1: undefined method `lcm' for 5:Fixnum (NoMethodError)
logan:/Users/logan% ruby -rubygems -e 'p(5.lcm(3))'
15
logan:/Users/logan% ruby -v
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
logan:/Users/logan% gem -v
0.8.10

irb(main):001:0> old_features = $LOADED_FEATURES.dup
=> ["irb.rb", "e2mmap.rb", "irb/init.rb", "irb/context.rb", "irb/ 
workspace.rb", "irb/extend-command.rb", "irb/ruby-lex.rb", "irb/ 
slex.rb", "irb/ruby-token.rb", "irb/input-method.rb",  
"readline.bundle", "irb/locale.rb", "tempfile.rb", "delegate.rb",  
"tmpdir.rb", "irb/completion.rb"]
irb(main):002:0> require 'ubygems'
=> true
irb(main):003:0> new_features = $LOADED_FEATURES - old_features
=> ["ubygems.rb", "rubygems.rb", "rbconfig.rb", "rubygems/ 
rubygems_version.rb", "rubygems/source_index.rb", "rubygems/ 
user_interaction.rb", "forwardable.rb", "rubygems/specification.rb",  
"date.rb", "rational.rb", "date/format.rb", "rubygems/version.rb",  
"rubygems/custom_require.rb"]